2.4 Using Automake

It is much easier if you use GNU Automake instead of writing your own Makefiles. If you do that you do not have to worry about finding and invoking the pkg-config script at all. GPGME provides an extension to Automake that does all the work for you.

Macro: AM_PATH_GPGME ([minimum-version], [action-if-found], [action-if-not-found]) ¶

Check whether GPGME (at least version minimum-version, if given) exists on the host system. If it is found, execute action-if-found, otherwise do action-if-not-found, if given.

This macro locates for gpgme.pc, with cross-compile support.

Additionally, the function defines GPGME_CFLAGS to the flags needed for compilation of the program to find the gpgme.h header file, and GPGME_LIBS to the linker flags needed to link the program to the GPGME library.

AM_PATH_GPGME_PTHREAD was provided to check for the version of GPGME with the native pthread implementation, and it defined GPGME_PTHREAD_CFLAGS and GPGME_PTHREAD_LIBS. Since version 1.8.0 this is no longer necessary, as GPGME itself is thread safe. Please use plain AM_PATH_GPGME instead, with GPGME_CFLAGS and GPGME_LDFLAGS.

You can use the defined Autoconf variables like this in your Makefile.am:

AM_CPPFLAGS = $(GPGME_CFLAGS)
LDADD = $(GPGME_LIBS)